The teachings presented herein relate generally to stereoscopic images. More specifically the teachings presented herein relate to the creation of stereoscopic images by printing on transparencies.
The principle of stereoscopic vision is well understood. At the most basic level, each of the viewer's two eyes must perceive the subject matter to be viewed from a slightly different perspective. That is to say that, although the differences are generally quite subtle, each eye receives a different image.
Several methods are commonly used to produce stereoscopic images. On the one hand, these include the use of direction selective screens onto which two or more images may be projected simultaneously. Depending on the viewer's position, a different image may be observed by each eye. Where only two images are required, it is common practice to use polarizing techniques. Each image is projected with a characteristic polarization and when viewing through complementary polarizing viewing spectacles, each eye only sees the picture intended for its reception.
Most existing methods to view printed stereoscopic images require either special glasses (colored or polarized) or lenticular lenses. The stereogram may be the one exception which does not need any special viewing aid, however, many people find that it is very difficult and uncomfortable to see the hidden stereo image. Lenticular lenses are common but incur some additional expense and complexity as they require an embossed transparent material for operation.
What is needed is a method and apparatus for providing stereoscopic rendering of images with depth and impact yet are viewable without the need for lenticular or other special lenses and which may be readily and inexpensively provided with common materials using conventional printing apparatus.
Disclosed in embodiments herein is a moiré-based auto-stereoscopic enhanced rendered image comprising image data segmented into a first partition and a second partition for enhanced rendering. The rendered image includes a transparent substrate having a first side and a second side, with a first side applied marking material having a periodic structure at a first frequency, as applied to and placed on the first side of the transparent substrate. The rendered image also includes a second side applied marking material for rendering the image data as applied to the second side of the transparent substrate. The second side applied marking material further comprising for the image data first partition, a second periodic halftone structure at a second frequency, that second frequency being related to but some delta away from the first frequency, and for the image data second partition, a third periodic halftone structure at a third frequency, that third frequency being related to but some delta away from the first frequency, such that when the rendered transparent substrate is viewed from either side a moiré-based auto-stereoscopic enhanced rendered image is evident.
Further disclosed in embodiments herein is a method for providing an enhanced moiré-based auto-stereoscopic rendered image, by segmenting image data to be rendered into two partitions, as well as applying marking material with a halftone periodic structure at a first frequency to the first side of a transparent substrate. The method further comprises applying marking material within a first partition on the second side of the transparent substrate with a halftone periodic structure at a second frequency, that second frequency being related to but some delta away from the first frequency. The method also comprises applying marking material within a second partition on the second side of the transparent substrate with a halftone periodic structure at a third frequency, that third frequency being related to but some delta away from the first frequency such that a auto-stereoscopic moiré image is rendered.
Further disclosed in embodiments herein is a method for providing an enhanced moiré-based auto-stereoscopic rendered image, by segmenting image data to be rendered into two partitions, as well as applying marking material with a halftone periodic structure at a first frequency to the first side of a transparent substrate. The method further comprises applying marking material within a first partition on the second side of the transparent substrate with a halftone periodic structure at a second frequency, that second frequency being related to but some delta away from the first frequency. The method also comprises applying marking material within a second partition on the second side of the transparent substrate with a halftone periodic structure at the first frequency, such that a auto-stereoscopic moiré image is rendered.